--- /dev/null
+/*
+ * event tracer
+ *
+ * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ * - Added format output of fields of the trace point.
+ * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+
+#include "trace_output.h"
+
+#define TRACE_SYSTEM "TRACE_SYSTEM"
+
+static DEFINE_MUTEX(event_mutex);
+
+int trace_define_field(struct ftrace_event_call *call, char *type,
+ char *name, int offset, int size)
+{
+ struct ftrace_event_field *field;
+
+ field = kzalloc(sizeof(*field), GFP_KERNEL);
+ if (!field)
+ goto err;
+
+ field->name = kstrdup(name, GFP_KERNEL);
+ if (!field->name)
+ goto err;
+
+ field->type = kstrdup(type, GFP_KERNEL);
+ if (!field->type)
+ goto err;
+
+ field->offset = offset;
+ field->size = size;
+ list_add(&field->link, &call->fields);
+
+ return 0;
+
+err:
+ if (field) {
+ kfree(field->name);
+ kfree(field->type);
+ }
+ kfree(field);
+
+ return -ENOMEM;
+}
+
+static void ftrace_clear_events(void)
+{
+ struct ftrace_event_call *call = (void *)__start_ftrace_events;
+
+
+ while ((unsigned long)call < (unsigned long)__stop_ftrace_events) {
+
+ if (call->enabled) {
+ call->enabled = 0;
+ call->unregfunc();
+ }
+ call++;
+ }
+}
+
+static void ftrace_event_enable_disable(struct ftrace_event_call *call,
+ int enable)
+{
+
+ switch (enable) {
+ case 0:
+ if (call->enabled) {
+ call->enabled = 0;
+ call->unregfunc();
+ }
+ break;
+ case 1:
+ if (!call->enabled) {
+ call->enabled = 1;
+ call->regfunc();
+ }
+ break;
+ }
+}
+
+static int ftrace_set_clr_event(char *buf, int set)
+{
+ struct ftrace_event_call *call = __start_ftrace_events;
+ char *event = NULL, *sub = NULL, *match;
+ int ret = -EINVAL;
+
+ /*
+ * The buf format can be <subsystem>:<event-name>
+ * *:<event-name> means any event by that name.
+ * :<event-name> is the same.
+ *
+ * <subsystem>:* means all events in that subsystem
+ * <subsystem>: means the same.
+ *
+ * <name> (no ':') means all events in a subsystem with
+ * the name <name> or any event that matches <name>
+ */
+
+ match = strsep(&buf, ":");
+ if (buf) {
+ sub = match;
+ event = buf;
+ match = NULL;
+
+ if (!strlen(sub) || strcmp(sub, "*") == 0)
+ sub = NULL;
+ if (!strlen(event) || strcmp(event, "*") == 0)
+ event = NULL;
+ }
+
+ mutex_lock(&event_mutex);
+ for_each_event(call) {
+
+ if (!call->name || !call->regfunc)
+ continue;
+
+ if (match &&
+ strcmp(match, call->name) != 0 &&
+ strcmp(match, call->system) != 0)
+ continue;
+
+ if (sub && strcmp(sub, call->system) != 0)
+ continue;
+
+ if (event && strcmp(event, call->name) != 0)
+ continue;
+
+ ftrace_event_enable_disable(call, set);
+
+ ret = 0;
+ }
+ mutex_unlock(&event_mutex);
+
+ return ret;
+}
+
+/* 128 should be much more than enough */
+#define EVENT_BUF_SIZE 127
+
+static ssize_t
+ftrace_event_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ size_t read = 0;
+ int i, set = 1;
+ ssize_t ret;
+ char *buf;
+ char ch;
+
+ if (!cnt || cnt < 0)
+ return 0;
+
+ ret = tracing_update_buffers();
+ if (ret < 0)
+ return ret;
+
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ return ret;
+ read++;
+ cnt--;
+
+ /* skip white space */
+ while (cnt && isspace(ch)) {
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ return ret;
+ read++;
+ cnt--;
+ }
+
+ /* Only white space found? */
+ if (isspace(ch)) {
+ file->f_pos += read;
+ ret = read;
+ return ret;
+ }
+
+ buf = kmalloc(EVENT_BUF_SIZE+1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ if (cnt > EVENT_BUF_SIZE)
+ cnt = EVENT_BUF_SIZE;
+
+ i = 0;
+ while (cnt && !isspace(ch)) {
+ if (!i && ch == '!')
+ set = 0;
+ else
+ buf[i++] = ch;
+
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out_free;
+ read++;
+ cnt--;
+ }
+ buf[i] = 0;
+
+ file->f_pos += read;
+
+ ret = ftrace_set_clr_event(buf, set);
+ if (ret)
+ goto out_free;
+
+ ret = read;
+
+ out_free:
+ kfree(buf);
+
+ return ret;
+}
+
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct ftrace_event_call *call = m->private;
+ struct ftrace_event_call *next = call;
+
+ (*pos)++;
+
+ for (;;) {
+ if ((unsigned long)call >= (unsigned long)__stop_ftrace_events)
+ return NULL;
+
+ /*
+ * The ftrace subsystem is for showing formats only.
+ * They can not be enabled or disabled via the event files.
+ */
+ if (call->regfunc)
+ break;
+
+ call++;
+ next = call;
+ }
+
+ m->private = ++next;
+
+ return call;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+ return t_next(m, NULL, pos);
+}
+
+static void *
+s_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct ftrace_event_call *call = m->private;
+ struct ftrace_event_call *next;
+
+ (*pos)++;
+
+ retry:
+ if ((unsigned long)call >= (unsigned long)__stop_ftrace_events)
+ return NULL;
+
+ if (!call->enabled) {
+ call++;
+ goto retry;
+ }
+
+ next = call;
+ m->private = ++next;
+
+ return call;
+}
+
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+ return s_next(m, NULL, pos);
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+ struct ftrace_event_call *call = v;
+
+ if (strcmp(call->system, TRACE_SYSTEM) != 0)
+ seq_printf(m, "%s:", call->system);
+ seq_printf(m, "%s\n", call->name);
+
+ return 0;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+}
+
+static int
+ftrace_event_seq_open(struct inode *inode, struct file *file)
+{
+ int ret;
+ const struct seq_operations *seq_ops;
+
+ if ((file->f_mode & FMODE_WRITE) &&
+ !(file->f_flags & O_APPEND))
+ ftrace_clear_events();
+
+ seq_ops = inode->i_private;
+ ret = seq_open(file, seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+
+ m->private = __start_ftrace_events;
+ }
+ return ret;
+}
+
+static ssize_t
+event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct ftrace_event_call *call = filp->private_data;
+ char *buf;
+
+ if (call->enabled)
+ buf = "1\n";
+ else
+ buf = "0\n";
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+}
+
+static ssize_t
+event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct ftrace_event_call *call = filp->private_data;
+ char buf[64];
+ unsigned long val;
+ int ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ ret = tracing_update_buffers();
+ if (ret < 0)
+ return ret;
+
+ switch (val) {
+ case 0:
+ case 1:
+ mutex_lock(&event_mutex);
+ ftrace_event_enable_disable(call, val);
+ mutex_unlock(&event_mutex);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+#undef FIELD
+#define FIELD(type, name) \
+ #type, "common_" #name, offsetof(typeof(field), name), \
+ sizeof(field.name)
+
+static int trace_write_header(struct trace_seq *s)
+{
+ struct trace_entry field;
+
+ /* struct trace_entry */
+ return trace_seq_printf(s,
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\n",
+ FIELD(unsigned char, type),
+ FIELD(unsigned char, flags),
+ FIELD(unsigned char, preempt_count),
+ FIELD(int, pid),
+ FIELD(int, tgid));
+}
+
+static ssize_t
+event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct ftrace_event_call *call = filp->private_data;
+ struct trace_seq *s;
+ char *buf;
+ int r;
+
+ if (*ppos)
+ return 0;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ trace_seq_init(s);
+
+ /* If any of the first writes fail, so will the show_format. */
+
+ trace_seq_printf(s, "name: %s\n", call->name);
+ trace_seq_printf(s, "ID: %d\n", call->id);
+ trace_seq_printf(s, "format:\n");
+ trace_write_header(s);
+
+ r = call->show_format(s);
+ if (!r) {
+ /*
+ * ug! The format output is bigger than a PAGE!!
+ */
+ buf = "FORMAT TOO BIG\n";
+ r = simple_read_from_buffer(ubuf, cnt, ppos,
+ buf, strlen(buf));
+ goto out;
+ }
+
+ r = simple_read_from_buffer(ubuf, cnt, ppos,
+ s->buffer, s->len);
+ out:
+ kfree(s);
+ return r;
+}
+
+static ssize_t
+event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ struct ftrace_event_call *call = filp->private_data;
+ struct trace_seq *s;
+ int r;
+
+ if (*ppos)
+ return 0;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ trace_seq_init(s);
+ trace_seq_printf(s, "%d\n", call->id);
+
+ r = simple_read_from_buffer(ubuf, cnt, ppos,
+ s->buffer, s->len);
+ kfree(s);
+ return r;
+}
+
+static ssize_t
+event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct ftrace_event_call *call = filp->private_data;
+ struct trace_seq *s;
+ int r;
+
+ if (*ppos)
+ return 0;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ trace_seq_init(s);
+
+ filter_print_preds(call->preds, s);
+ r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
+
+ kfree(s);
+
+ return r;
+}
+
+static ssize_t
+event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct ftrace_event_call *call = filp->private_data;
+ char buf[64], *pbuf = buf;
+ struct filter_pred *pred;
+ int err;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ pred = kzalloc(sizeof(*pred), GFP_KERNEL);
+ if (!pred)
+ return -ENOMEM;
+
+ err = filter_parse(&pbuf, pred);
+ if (err < 0) {
+ filter_free_pred(pred);
+ return err;
+ }
+
+ if (pred->clear) {
+ filter_free_preds(call);
+ filter_free_pred(pred);
+ return cnt;
+ }
+
+ if (filter_add_pred(call, pred)) {
+ filter_free_pred(pred);
+ return -EINVAL;
+ }
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static ssize_t
+subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct event_subsystem *system = filp->private_data;
+ struct trace_seq *s;
+ int r;
+
+ if (*ppos)
+ return 0;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ trace_seq_init(s);
+
+ filter_print_preds(system->preds, s);
+ r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
+
+ kfree(s);
+
+ return r;
+}
+
+static ssize_t
+subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct event_subsystem *system = filp->private_data;
+ char buf[64], *pbuf = buf;
+ struct filter_pred *pred;
+ int err;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ pred = kzalloc(sizeof(*pred), GFP_KERNEL);
+ if (!pred)
+ return -ENOMEM;
+
+ err = filter_parse(&pbuf, pred);
+ if (err < 0) {
+ filter_free_pred(pred);
+ return err;
+ }
+
+ if (pred->clear) {
+ filter_free_subsystem_preds(system);
+ filter_free_pred(pred);
+ return cnt;
+ }
+
+ if (filter_add_subsystem_pred(system, pred)) {
+ filter_free_subsystem_preds(system);
+ filter_free_pred(pred);
+ return -EINVAL;
+ }
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static const struct seq_operations show_event_seq_ops = {
+ .start = t_start,
+ .next = t_next,
+ .show = t_show,
+ .stop = t_stop,
+};
+
+static const struct seq_operations show_set_event_seq_ops = {
+ .start = s_start,
+ .next = s_next,
+ .show = t_show,
+ .stop = t_stop,
+};
+
+static const struct file_operations ftrace_avail_fops = {
+ .open = ftrace_event_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static const struct file_operations ftrace_set_event_fops = {
+ .open = ftrace_event_seq_open,
+ .read = seq_read,
+ .write = ftrace_event_write,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static const struct file_operations ftrace_enable_fops = {
+ .open = tracing_open_generic,
+ .read = event_enable_read,
+ .write = event_enable_write,
+};
+
+static const struct file_operations ftrace_event_format_fops = {
+ .open = tracing_open_generic,
+ .read = event_format_read,
+};
+
+static const struct file_operations ftrace_event_id_fops = {
+ .open = tracing_open_generic,
+ .read = event_id_read,
+};
+
+static const struct file_operations ftrace_event_filter_fops = {
+ .open = tracing_open_generic,
+ .read = event_filter_read,
+ .write = event_filter_write,
+};
+
+static const struct file_operations ftrace_subsystem_filter_fops = {
+ .open = tracing_open_generic,
+ .read = subsystem_filter_read,
+ .write = subsystem_filter_write,
+};
+
+static struct dentry *event_trace_events_dir(void)
+{
+ static struct dentry *d_tracer;
+ static struct dentry *d_events;
+
+ if (d_events)
+ return d_events;
+
+ d_tracer = tracing_init_dentry();
+ if (!d_tracer)
+ return NULL;
+
+ d_events = debugfs_create_dir("events", d_tracer);
+ if (!d_events)
+ pr_warning("Could not create debugfs "
+ "'events' directory\n");
+
+ return d_events;
+}
+
+static LIST_HEAD(event_subsystems);
+
+static struct dentry *
+event_subsystem_dir(const char *name, struct dentry *d_events)
+{
+ struct event_subsystem *system;
+
+ /* First see if we did not already create this dir */
+ list_for_each_entry(system, &event_subsystems, list) {
+ if (strcmp(system->name, name) == 0)
+ return system->entry;
+ }
+
+ /* need to create new entry */
+ system = kmalloc(sizeof(*system), GFP_KERNEL);
+ if (!system) {
+ pr_warning("No memory to create event subsystem %s\n",
+ name);
+ return d_events;
+ }
+
+ system->entry = debugfs_create_dir(name, d_events);
+ if (!system->entry) {
+ pr_warning("Could not create event subsystem %s\n",
+ name);
+ kfree(system);
+ return d_events;
+ }
+
+ system->name = name;
+ list_add(&system->list, &event_subsystems);
+
+ system->preds = NULL;
+
+ return system->entry;
+}
+
+static int
+event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
+{
+ struct dentry *entry;
+ int ret;
+
+ /*
+ * If the trace point header did not define TRACE_SYSTEM
+ * then the system would be called "TRACE_SYSTEM".
+ */
+ if (strcmp(call->system, "TRACE_SYSTEM") != 0)
+ d_events = event_subsystem_dir(call->system, d_events);
+
+ if (call->raw_init) {
+ ret = call->raw_init();
+ if (ret < 0) {
+ pr_warning("Could not initialize trace point"
+ " events/%s\n", call->name);
+ return ret;
+ }
+ }
+
+ call->dir = debugfs_create_dir(call->name, d_events);
+ if (!call->dir) {
+ pr_warning("Could not create debugfs "
+ "'%s' directory\n", call->name);
+ return -1;
+ }
+
+ if (call->regfunc) {
+ entry = debugfs_create_file("enable", 0644, call->dir, call,
+ &ftrace_enable_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'%s/enable' entry\n", call->name);
+ }
+
+ if (call->id) {
+ entry = debugfs_create_file("id", 0444, call->dir, call,
+ &ftrace_event_id_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs '%s/id' entry\n",
+ call->name);
+ }
+
+ if (call->define_fields) {
+ ret = call->define_fields();
+ if (ret < 0) {
+ pr_warning("Could not initialize trace point"
+ " events/%s\n", call->name);
+ return ret;
+ }
+ entry = debugfs_create_file("filter", 0644, call->dir, call,
+ &ftrace_event_filter_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'%s/filter' entry\n", call->name);
+ }
+
+ /* A trace may not want to export its format */
+ if (!call->show_format)
+ return 0;
+
+ entry = debugfs_create_file("format", 0444, call->dir, call,
+ &ftrace_event_format_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'%s/format' entry\n", call->name);
+
+ return 0;
+}
+
+static __init int event_trace_init(void)
+{
+ struct ftrace_event_call *call = __start_ftrace_events;
+ struct dentry *d_tracer;
+ struct dentry *entry;
+ struct dentry *d_events;
+
+ d_tracer = tracing_init_dentry();
+ if (!d_tracer)
+ return 0;
+
+ entry = debugfs_create_file("available_events", 0444, d_tracer,
+ (void *)&show_event_seq_ops,
+ &ftrace_avail_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'available_events' entry\n");
+
+ entry = debugfs_create_file("set_event", 0644, d_tracer,
+ (void *)&show_set_event_seq_ops,
+ &ftrace_set_event_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'set_event' entry\n");
+
+ d_events = event_trace_events_dir();
+ if (!d_events)
+ return 0;
+
+ for_each_event(call) {
+ /* The linker may leave blanks */
+ if (!call->name)
+ continue;
+ event_create_dir(call, d_events);
+ }
+
+ return 0;
+}
+fs_initcall(event_trace_init);
projects / linux-2.6-omap-h63xx.git / blobdiff